Metallic laminate and manufacturing method of light emitting diode package using the same

ABSTRACT

The present invention relates to a metallic laminate and a manufacturing method of a light emitting diode package using the same. The present invention provides a metallic laminate including: a core layer made of an insulating material; a metal layer disposed on one surface of the core layer; a heat radiating metal layer disposed on the other surface of the core layer; and a protective metal oxide layer disposed along an outer surface of the heat radiating metal layer and made of an oxide of the heat radiating metal layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No.10-2009-0046991 filed with the Korea Intellectual Property Office on May28, 2009, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a metallic laminate and a manufacturingmethod of a light emitting diode package using the same, and moreparticularly, to a metallic laminate having a protective metal oxidelayer disposed along an outer surface of a heat radiating metal layerand made of an oxide of the heat radiating metal layer, and amanufacturing method of a light emitting diode package using the same.

2. Description of the Related Art

In general, a light emitting diode device is widely used as a lightsource because of several advantages such as low power consumption andhigh brightness.

Especially recently, the light emitting diode device is employed as alighting device and a backlight for a liquid crystal display (LCD). Thislight emitting diode device is provided in the form of a package whichis easily mounted to various devices such as lighting devices.

The light emitting diode package includes a light emitting diode devicewhich is mounted on a printed circuit board. Here, the light emittingdiode device generates heat together with light. At this time, the heatgenerated from the light emitting diode device is radiated through theprinted circuit board. However, since the printed circuit board is madeof an insulating material having low heat conduction efficiency, theconventional light emitting diode package can't efficiently radiate theheat generated from the light emitting diode device. Therefore, there isa problem of deterioration of life and characteristics of the lightemitting diode device.

As one way to solve this problem, there has been proposed a technologyof forming a through hole in a printed circuit board of a mountingregion of a light emitting diode device and filling the through holewith a heat conductive material, but there are problems of complexity ofa manufacturing process and increase of a manufacturing cost.

Accordingly, it is possible to improve heat radiating efficiency andsimplify the manufacturing process by directly mounting the lightemitting diode package on a package substrate which includes Al withheat radiating effect on a lower surface.

However, in order to prevent corrosion of Al due to chemicals used in aprocess of forming a circuit pattern, which is electrically connected tothe light emitting diode device, on the package substrate, an additionaltape should be attached to a surface of Al. At this time, additionalprocess and manpower for attaching and detaching the tape are required,and failure of the package substrate or a process may be caused bypollutants generated due to damage of the tape during the process.

Therefore, in order to achieve heat radiating effect and processsimplification, the conventional light emitting diode package includesthe package substrate having the Al layer, but there is a problem ofincrease of failures and the number of processes due to the tapeattaching process for protecting Al from the chemicals.

SUMMARY OF THE INVENTION

The present invention has been proposed in order to solve theabove-described problems, and it is, therefore, an object of the presentinvention to provide a metallic laminate having a protective metal oxidelayer disposed along an outer surface of a heat radiating metal layerand made of an oxide of the heat radiating metal layer, and amanufacturing method of a light emitting diode package using the same.

In accordance with an aspect of the present invention to achieve theobject, there is provided a metallic laminate including: a core layermade of an insulating material; a metal layer disposed on one surface ofthe core layer; a heat radiating metal layer disposed on the othersurface of the core layer; and a protective metal oxide layer disposedalong an outer surface of the heat radiating metal layer and made of anoxide of the heat radiating metal layer.

Here, the core layer may further include a heat radiating filler.

Further, the heat radiating metal layer may include aluminum, and theprotective metal oxide layer may include an aluminum oxide film.

Further, the metal layer may be made of any one of copper or a copperalloy.

In accordance with another aspect of the present invention to achievethe object, there is provided a manufacturing method of a light emittingdiode package including the steps of: preparing a metallic laminateincluding a core layer made of an insulating material, a metal layerdisposed on one surface of the core layer, a heat radiating metal layerdisposed on the other surface of the core layer, and a protective metaloxide layer disposed along an outer surface of the heat radiating metallayer and made of an oxide of the heat radiating metal layer; forming acircuit pattern electrically connected to a light emitting diode bypatterning the metal layer; and mounting a light emitting diode deviceon the circuit pattern.

Here, the protective metal oxide layer may be formed by anodizing thesurface of the heat radiating metal layer.

Further, the heat radiating metal layer may be made of aluminum, and theprotective metal oxide layer may be made of an aluminum oxide film.

Further, the method may further include the step of removing theprotective metal oxide layer between the step of forming the circuitpattern and the step of mounting the light emitting diode device.

Further, the core layer may further include a heat radiating filler.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the present generalinventive concept will become apparent and more readily appreciated fromthe following description of the embodiments, taken in conjunction withthe accompanying drawings of which:

FIG. 1 is a cross-sectional view of a metallic laminate in accordancewith a first embodiment of the present invention;

FIG. 2 is a cross-sectional view of a light emitting diode packagehaving a metallic laminate in accordance with a first embodiment of thepresent invention; and

FIGS. 3 to 6 are cross-sectional views for describing a manufacturingmethod of a light emitting diode package in accordance with a secondembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will beexplained in detail with reference to the drawings of a metalliclaminate and a light emitting diode package. It should be understoodthat the following embodiments will be provided as examples to allowthose skilled in the art to fully understand the spirit of the presentinvention. Therefore, the present invention is not limited to thefollowing embodiments but may be embodied in other forms. And, in thedrawings, sizes and thicknesses of elements may be exaggerated forconvenience. Like reference numerals refer to like elements throughout.

FIG. 1 is a cross-sectional view of a metallic laminate in accordancewith a first embodiment of the present invention.

Referring to FIG. 1, a metallic laminate includes a core layer 110, ametal layer 120, a heat radiating metal layer 130, and a protectivemetal oxide layer 140.

The core layer 110 is made of an insulating material. For example, thecore layer 110 may include an epoxy resin or a phenolic resin. Further,the core layer 110 may further include glass fiber to improvedurability.

In addition, the core layer 110 further include a heat radiating filler111. The heat radiating filler 111 is a heat conductive material havinghigh heat conductivity, for example, powder of any one of silver,nickel, copper, aluminum, graphite, ferrite, and carbon. Accordingly,the core layer 110 more efficiently transmits heat from the metal layer120 to the heat radiating metal layer 130.

The metal layer 120 is disposed on one surface of the core layer 110.The metal layer 120 is a conductive film for forming a circuit pattern.For example, the metal layer 120 may be made of copper or a copperalloy.

The heat radiating metal layer 130 is disposed on the other surface ofthe core layer 110. The heat radiating metal layer 130 is made of metalhaving high heat conductivity, for example, aluminum. However, in theembodiment of the present invention, a material of the heat radiatingmetal layer 130 is not limited.

The protective metal oxide layer 140 is disposed along an outerperipheral surface of the heat radiating metal layer 130. That is, theprotective metal oxide layer 140 is formed to cover the surface of theheat radiating metal layer 130, which is exposed to the outside. Theprotective metal oxide layer 140 plays a role of preventing corrosion ofthe heat radiating metal layer 130 due to chemicals used in a patterningprocess of the metal layer 120 or external oxygen or moisture. At thistime, the protective metal oxide layer 140 is made of an oxide of theheat radiating metal layer 130. That is, the protective metal oxidelayer 140 is formed by surface oxidation of the heat radiating metallayer 130 due to anodizing. For example, in case that the heat radiatingmetal layer 130 is made of aluminum, the protective metal oxide layer140 is made of an aluminum oxide. Accordingly, the heat radiating metallayer 130 is formed by an easy process such as surface oxidation.

Therefore, like the embodiment of the present invention, it is possibleto improve heat radiating efficiency of a light emitting diode packageby forming a circuit board of the light emitting diode package with asubstrate having the heat radiating metal layer.

Further, it is possible to prevent the corrosion of the heat radiatingmetal layer in a process of forming the circuit pattern by furtherproviding the protective metal oxide layer on the surface of the heatradiating metal layer.

Hereinafter, a light emitting diode package manufactured from a metalliclaminate in accordance with a first embodiment of the present inventionwill be described with reference to FIG. 2.

FIG. 2 is a cross-sectional view of a light emitting diode packagehaving a metallic laminate in accordance with a first embodiment of thepresent invention.

Referring to FIG. 2, a light emitting diode package includes a packagesubstrate 200 and a light emitting diode 250 mounted on the packagesubstrate 200.

The package substrate 200 includes a core layer 210 made of aninsulating material, a circuit pattern 220 disposed on an upper surfaceof the core layer 210, and a heat radiating metal layer 230 disposed ona lower surface of the core layer 210.

The light emitting diode 250 is electrically connected to the circuitpattern 220 and mounted on the package substrate 200 by wire 260bonding. For example, in case that the light emitting diode 250 is avertical light emitting diode, a lower surface of the light emittingdiode 250 is directly electrically bonded to the circuit pattern 220,and an upper surface of the light emitting diode 250 is electricallybonded to the circuit pattern 220 by the wire 260 bonding. However, inthe embodiment of the present invention, a shape of the light emittingdiode 250 is not limited, and the light emitting diode 250 may bemounted on the package substrate 200 by flip chip bonding.

The core layer 210 further includes a heat radiating filler 211 forefficiently conducting heat from the circuit pattern 220 to the heatradiating metal layer 230. The heat radiating filler 211 may be heatconductive powder of any one of silver, nickel, copper, aluminum,graphite, ferrite, and carbon.

The heat radiating metal layer 230 plays a role of radiating heatgenerated from the light emitting diode 250 mounted on the packagesubstrate 200 to the outside.

Accordingly, since the light emitting diode 250 is directly mounted onthe package substrate 200 having the heat radiating metal layer 230, itis possible to efficiently radiate the heat to the outside, therebyimproving life of the light emitting diode 250 and securing reliability.

In addition, a protective metal oxide layer 240 is disposed along anouter surface of the heat radiating metal layer 230 to protect the heatradiating metal layer 230 in a manufacturing process of the lightemitting diode package. The protective metal oxide layer 240 is made ofan oxide of metal forming the heat radiating metal layer 230.Accordingly, the protective metal oxide layer 240 is easily manufacturedby anodizing the heat radiating metal layer 230.

In the embodiment of the present invention, although it is shown anddescribed that the light emitting diode package includes the protectivemetal oxide layer 240, the protective metal oxide layer 240 may beremoved in a manufacturing completion process of the light emittingdiode package.

In addition, the light emitting diode package further includes a moldingportion 270 which covers the light emitting diode 250. The moldingportion 270 plays a role of protecting the light emitting diode 250 fromthe outside. The molding portion 270 may be made of a transparent resin,for example, a silicon resin, an epoxy resin, a urethane resin, and anepoxy molding compound. In addition, the molding portion 270 may furtherinclude a fluorescent material which converts a wavelength of lightemitted from the light emitting diode 250. Accordingly, the moldingportion 270 may perform a wavelength conversion function as well asprotect the light emitting diode 250.

Therefore, like the embodiment of the present invention, it is possibleto easily radiate the heat generated from the light emitting diode tothe outside without thickness change of the light emitting diode packageor addition of a separate process by forming the package substrate ofthe light emitting diode package with a metallic laminate having theheat radiating metal layer instead of a printed circuit board.

Hereinafter, a manufacturing method of a light emitting diode packageusing a metallic laminate in accordance with a first embodiment of thepresent invention will be described with reference to FIGS. 3 to 6.

FIGS. 3 to 6 are cross-sectional views for describing a manufacturingmethod of a light emitting diode package in accordance with a secondembodiment of the present invention

Referring to FIG. 3, in order to manufacture a light emitting diodepackage, first, a metallic laminate is formed.

In order to manufacture the metallic laminate, a core layer 210 made ofan insulating material is provided. The core layer 210 may include anepoxy resin or a phenolic resin. Further, the core layer 210 may furtherinclude glass fiber to improve durability. Further, the core layerfurther includes a heat radiating filler 211 to improve heat radiatingeffect of the metallic laminate. For example, the heat radiating filler211 may be made of silver, nickel, copper, aluminum, graphite, ferrite,or carbon.

The metal laminate is formed by respectively stacking a metal layer 220a and a heat radiating metal layer 230 on both surfaces of the corelayer 210 and heating and pressing them.

The metal layer 220 a is made of a conductive material, for example,copper or a copper alloy.

Further, the heat radiating metal layer 230 is made of a material havinghigher heat conductivity than other materials, for example, aluminum oran aluminum alloy.

Referring to FIG. 4, a protective metal oxide layer 240 is formed alongan outer surface of the heat radiating metal layer 230. That is, theprotective metal oxide layer 240 is formed on the surface of the heatradiating metal layer 230, which is exposed to the outside. Theprotective metal oxide layer 240 plays a role of preventing corrosion ofthe heat radiating metal layer 230 due to chemicals used in a patterningprocess of the metal layer 220 a.

The protective metal oxide layer 240 is made of an oxide of metalforming the heat radiating metal layer 230. For example, in case thatthe heat radiating metal layer 230 is made of aluminum, the protectivemetal oxide layer 240 is made of an aluminum oxide.

At this time, the protective metal oxide layer 240 is formed byanodizing the heat radiating metal layer 230. Here, for example, theanodizing method may be a sulfuric acid method, a hydrofluoric acidmethod, or an organic acid method.

Accordingly, since additional process and manpower for attaching aprotective tape to protect the heat radiating metal layer 230 are notrequired, it is possible to reduce the number of processes and a processcost and to protect the surface of the heat radiating metal layer 230.

Referring to FIG. 5, a circuit pattern 220 is formed by etching themetal layer 220 a. At this time, the protective metal oxide layer 240protects the surface of the heat radiating metal layer 230 fromchemicals used in a process of forming the circuit pattern 220.

Referring to FIG. 6, a light emitting diode 250 is mounted to beelectrically connected to the circuit pattern 220. Here, the lightemitting diode 250 is mounted by a wire 260 bonding method or a flipchip bonding method, and it is not limited in the embodiment of thepresent invention.

After that, a molding portion 260 is formed to cover the light emittingdiode 250. The molding portion 260 may be made of a silicon resin, anepoxy resin, a urethane resin, or an epoxy molding compound. Inaddition, the molding portion 260 may further include a fluorescentmaterial for converting light generated from the light emitting diode250. Here, for example, the molding portion 260 may be formed in adesired shape by a casting mold method, a dispensing method, aninjection molding method, a transfer molding method, or a pin gatemolding method.

In addition, a process of removing the protective metal oxide layer 240by a wet method may be further performed.

Accordingly, like the embodiment of the present invention, it ispossible to improve heat radiating efficiency of the light emittingdiode package and to manufacture the light emitting diode packagethrough an easy manufacturing process by forming a package substratewith the metallic laminate having high heat conductivity.

Further, it is possible to prevent deterioration of the heat radiatingefficiency by protecting the surface of the heat radiating metal layerof the metallic laminate with the protective metal oxide layer.

Further, it is possible to prevent increase of a process cost withoutpurchasing subsidiary materials by easily forming the protective metaloxide layer with the anodizing method of the heat radiating metal layer.

The present invention manufactures the light emitting diode packagehaving high heat radiating efficiency through the easy process byforming the package substrate with the metallic laminate having themetal layer, the core layer, and the heat radiating metal layer.

Further, it is possible to protect the heat radiating metal layer fromthe chemicals used in the process of forming the circuit pattern byforming the protective metal oxide layer on the outer surface of theheat radiating metal layer.

Further, it is possible to easily form the protective metal oxide layerby anodizing the heat radiating metal layer.

Although a few embodiments of the present general inventive concept havebeen shown and described, it will be appreciated by those skilled in theart that changes may be made in these embodiments without departing fromthe principles and spirit of the general inventive concept, the scope ofwhich is defined in the appended claims and their equivalents.

1. A metallic laminate comprising: a core layer made of an insulatingmaterial; a metal layer disposed on one surface of the core layer; aheat radiating metal layer disposed on the other surface of the corelayer; and a protective metal oxide layer disposed along an outersurface of the heat radiating metal layer and made of an oxide of theheat radiating metal layer.
 2. The metallic laminate according to claim1, wherein the core layer further includes a heat radiating filler. 3.The metallic laminate according to claim 1, wherein the heat radiatingmetal layer includes aluminum and the protective metal oxide layerincludes an aluminum oxide film.
 4. The metallic laminate according toclaim 1, wherein the metal layer is made of copper or a copper alloy. 5.A manufacturing method of a light emitting diode package comprising thesteps of: preparing a metallic laminate including a core layer made ofan insulating material, a metal layer disposed on one surface of thecore layer, a heat radiating metal layer disposed on the other surfaceof the core layer, and a protective metal oxide layer disposed along anouter surface of the heat radiating metal layer and made of an oxide ofthe heat radiating metal layer; forming a circuit pattern electricallyconnected to a light emitting diode by patterning the metal layer; andmounting a light emitting diode device on the circuit pattern.
 6. Themethod according to claim 5, wherein the protective metal oxide layer isformed by anodizing the surface of the heat radiating metal layer. 7.The method according to claim 5, wherein the heat radiating metal layeris made of aluminum, and the protective metal oxide layer is made of analuminum oxide film.
 8. The method according to claim 5, between thestep of forming the circuit pattern and the step of mounting the lightemitting diode device, further comprising the step of removing theprotective metal oxide layer.
 9. The method according to claim 5,wherein the core layer further includes a heat radiating filler.